Varnish and Wood sealer recommendation for Bare Mahogany wood hull

[mrsamimi]

Dear Gurus,

I need recommendations for Wood sealer and Varnish for Mahogany Hull, Bare wood, I need items I can but on Amazon US website, Can you please share your Favorite Varnish Brand and wood sealer?

I used Shellac, to finish the hull, did not work well and I had to sand down back to wood, there are very small areas of Shellac left but I think they will be covered with the wood sealer with no issue as Shellac was Zinnser Bulleye Sealer coat 100% wax free, from what I am gathering it can be used under any Varnish or anything else.

What I am hearing is some people use Wipe on poly but my issue is I have never done that and worried of causing bubbles and not being able to complete a good job, Also please tell me if there is a need to sanding between cats and how many cast I need.

Thanks for the help!

 

[Bryian]

You can use the shellac as a wood sealer, then wipe on poly for the topcoat. Do not be concerned about using the poly as it’s self leveling.

 

[mrsamimi]

You can use the shellac as a wood sealer, then wipe on poly for the topcoat. Do not be concerned about using the poly as it’s self leveling.

That sounds perfect! thank you for the answer, any good wipe on poly brand you can recommend? I want Matte finish, Also how would you apply the wipe on poly? With a brush or a rag? do you drop the poly on the model then wipe or pick with brush or rag first?

 

[Roger Pellett]

I’ve never used wipe on poly. Some modelers don’t like it as they say that it gives a “plastic” look. I would just buy a can of ordinary alkyd resin varnish at your local paint, hardware, or home improvement store. Varnishes are available in different glosses: Hi Gloss, Semi Gloss, Satin, and Matt. These can be thinned with mineral spirits (paint thinner). Once the varnish has FULLY CURED gloss can be flattened by rubbing with 0000 steel wool; or pumice or rotten stone on a rag.

Roger

 

[DAWarden-(Jaager)]

ou are asking for a quick pat answer to a situation that is complex and involves having some perspective.
If you intend to stick with this it is advisable that you go to school on this.
Buy a copy of Flexner. Read the relevant parts.
https://shipsofscale.com/sosforums/attachments/81skakgvj3l-_sl1500_-jpg.557760/
Get some boards to practice on. Do small windows of various options.
The Mahogany that you are working against is unlikely to be genuine Cuban or Honduran. It is probably an African species. It likely has open pores.
Yours is already well primed. Which is filling the near inside openings and blocking finish coats from soaking into the wood.
Unless you mixed some fine particles with the shellac to fill the open pores they would still be evident. Shellac alone is not a sealer.
A sealer is something "dirt" particles in it to fill the pores. A closed pore species of wood does not need - does not want a sealer.
Both open pore and closed pore need a primer. Shellac is as good a primer as can be had. It just wants knowledge and practice to get a good result.
Hence the practice board . Get Oak is you want practice with using a sealer. Get a more appropriate species like Birch, Yellow Poplar, Maple if it is just priming and finishing.
Shellac only - done properly The "dirt" can be added to the first dilute coat of shellac.
Shellac primed them boiled Linseed oil.
Shellac primed and polyurethane - wipe on poly is just dilute regular poly - it just costs more for the name and reduced volume of active ingredient.
Whatever other finishes interest you. Many options which if any satisfy you is your choice. Just practice first on something that does not matter.
Traditional sanding sealer is "dirt" in lacquer. Lacquer is a thick out-of-scale layer.
A good sanding gets you a new surface on your practice board.
Polyurethane just does not look like plastic - it is plastic. I just heat welded some 5mm polyurethane to make drive belts. It is stronger than stretchable rubber but it does not stretch much at all - it does not rot either.

 

[Bob Cleek]

What Roger and Jaager said. It depends on what sort of finish you want and what you're going to put it on. If you want a "bright" (clear) finish on your mahogany, the wood must be perfectly smooth with no open pores or your finish will simply accentuate the open pores. If it is open pored, you will have to apply a filler coating. This is a thicker material that is applied, allowed to partially dry, and then the excess is hand-rubbed off with a rough rag, leaving the residue in the pores. When completely dry, the surface is given a fine sanding to produce a uniformly smooth surface. (As always, read the instructions on the can!) You can then apply whatever finish coating you wish. As Jaager said, "wipe on poly" is just polyurethane varnish with thinner added, but costs the same. Thinner is a lot cheaper than polyurethane and you'll need some for cleanup anyway, so buy the regular polyurethane finish and thin it a bit. Just dip the corner of a folded clean cloth pad and wipe it on and then rub off the excess.

I would strongly recommend against using any sort of "satin" or "matte" finishes. As said previously, such finishes are only the base finish product with "dirt," (a fine powder, actually) added which causes the finish surface to be microscopically "rough" and thus less reflective, depending upon the amount of "flattener" added to the coating. The problem with this is twofold. First, such prepared clear finishes rarely, if ever, contain any UV shielding agents or "UV inhibitors" which provide protection from UV degradation, thus reducing the archival properties of the finish. Secondly, and most importantly, such "satin" finishes are very tricky to apply, especially if one does not read the instructions on the can! The flattening agents or "dirt," settle in the bottom of can and the material must be well stirred continually during application in order to uniformly suspend the flattening agent in the canned coating. The frequent scenario for inexperienced users who didn't read the instructions on the can is that they end up posting in forums like this asking why their "satin" finish dried with a high gloss and the answer is because the flattening agent is still sitting at the bottom of the can!

If a matte finish is desired (and it should be,) it is much better to apply a quality clear finish, allow it to dry well, and then hand-rub it using very fine steel wool (or bronze, if you have it, since there's no danger of fine bits of iron remaining to turn into ugly rust spots,) or with rottenstone and pumice. While hand-rubbing a finish is a bit more labor, it produces a markedly improved result because the fine abrasive rubbing not only "knocks the gloss down," but also removes any bits of dust that might have settled on the wet finish and would remain as defects that ruin the perfectly smooth finish.

Remember that when viewing a large, smooth surface, a viewer's eyes are naturally drawn to any deviation in the smoothness of the finish and any such distraction contributes to ruining the "compelling impression of reality" that is the whole point of a scale model. Modelers will often complain that their models "look like a toy," rather than the models they've seen in museums and glossy coffee table books. That is almost always the result of defects in the scale of the work and most frequently those defects are due to improper finishing. If your scale is 1:48 and your model viewing distance is three feet, then what you should "see" when looking at the model is what you would see if you were looking at the real vessel from a distance of about one hundred and fifty feet. If your eye is drawn to some finish blemish that is "seen" at its real size the impression of reality at scale is impaired.

Time invested in mastering the techniques of scale finishing is time well spent. Finishing fine scale models demands the painting skills of an artist, not a fence painter! While Floquil modeling paints are sadly no longer manufactured, Floquil's instructional manual on painting miniatures is available on the internet and modelers will find reading it a valuable resource. See: https://www.paulbudzik.com/tools-techniques/floquil-paint/Floquil Painting Miniatures.PDF Following the demise of Floquil miniatures paint, many experienced miniaturists have replaced it with tubed artists' oil paint, which can be obtained with high content finely ground quality pigments which can then be thinned and otherwise conditioned for modeling use.

 

[mrsamimi]

What Roger and Jaager said. It depends on what sort of finish you want and what you're going to put it on. If you want a "bright" (clear) finish on your mahogany, the wood must be perfectly smooth with no open pores or your finish will simply accentuate the open pores. If it is open pored, you will have to apply a filler coating. This is a thicker material that is applied, allowed to partially dry, and then the excess is hand-rubbed off with a rough rag, leaving the residue in the pores. When completely dry, the surface is given a fine sanding to produce a uniformly smooth surface. (As always, read the instructions on the can!) You can then apply whatever finish coating you wish. As Jaager said, "wipe on poly" is just polyurethane varnish with thinner added, but costs the same. Thinner is a lot cheaper than polyurethane and you'll need some for cleanup anyway, so buy the regular polyurethane finish and thin it a bit. Just dip the corner of a folded clean cloth pad and wipe it on and then rub off the excess.

I would strongly recommend against using any sort of "satin" or "matte" finishes. As said previously, such finishes are only the base finish product with "dirt," (a fine powder, actually) added which causes the finish surface to be microscopically "rough" and thus less reflective, depending upon the amount of "flattener" added to the coating. The problem with this is twofold. First, such prepared clear finishes rarely, if ever, contain any UV shielding agents or "UV inhibitors" which provide protection from UV degradation, thus reducing the archival properties of the finish. Secondly, and most importantly, such "satin" finishes are very tricky to apply, especially if one does not read the instructions on the can! The flattening agents or "dirt," settle in the bottom of can and the material must be well stirred continually during application in order to uniformly suspend the flattening agent in the canned coating. The frequent scenario for inexperienced users who didn't read the instructions on the can is that they end up posting in forums like this asking why their "satin" finish dried with a high gloss and the answer is because the flattening agent is still sitting at the bottom of the can!

If a matte finish is desired (and it should be,) it is much better to apply a quality clear finish, allow it to dry well, and then hand-rub it using very fine steel wool (or bronze, if you have it, since there's no danger of fine bits of iron remaining to turn into ugly rust spots,) or with rottenstone and pumice. While hand-rubbing a finish is a bit more labor, it produces a markedly improved result because the fine abrasive rubbing not only "knocks the gloss down," but also removes any bits of dust that might have settled on the wet finish and would remain as defects that ruin the perfectly smooth finish.

Remember that when viewing a large, smooth surface, a viewer's eyes are naturally drawn to any deviation in the smoothness of the finish and any such distraction contributes to ruining the "compelling impression of reality" that is the whole point of a scale model. Modelers will often complain that their models "look like a toy," rather than the models they've seen in museums and glossy coffee table books. That is almost always the result of defects in the scale of the work and most frequently those defects are due to improper finishing. If your scale is 1:48 and your model viewing distance is three feet, then what you should "see" when looking at the model is what you would see if you were looking at the real vessel from a distance of about one hundred and fifty feet. If your eye is drawn to some finish blemish that is "seen" at its real size the impression of reality at scale is impaired.

Time invested in mastering the techniques of scale finishing is time well spent. Finishing fine scale models demands the painting skills of an artist, not a fence painter! While Floquil modeling paints are sadly no longer manufactured, Floquil's instructional manual on painting miniatures is available on the internet and modelers will find reading it a valuable resource. See: https://www.paulbudzik.com/tools-techniques/floquil-paint/Floquil Painting Miniatures.PDF Following the demise of Floquil miniatures paint, many experienced miniaturists have replaced it with tubed artists' oil paint, which can be obtained with high content finely ground quality pigments which can then be thinned and otherwise conditioned for modeling use.

Great info, thank you very much for taking the time and answering so detailed. How about Tung Oil? Any advice on that? Looks like it is clear and acts as Sealer and finish.

 

[RussF]

Dear Gurus,

I need recommendations for Wood sealer and Varnish for Mahogany Hull, Bare wood, I need items I can but on Amazon US website, Can you please share your Favorite Varnish Brand and wood sealer?

I used Shellac, to finish the hull, did not work well and I had to sand down back to wood, there are very small areas of Shellac left but I think they will be covered with the wood sealer with no issue as Shellac was Zinnser Bulleye Sealer coat 100% wax free, from what I am gathering it can be used under any Varnish or anything else.

What I am hearing is some people use Wipe on poly but my issue is I have never done that and worried of causing bubbles and not being able to complete a good job, Also please tell me if there is a need to sanding between cats and how many cast I need.

Thanks for the help!

Ask 100 woodworkers about the "best" finish and you will get 100 different answers. It all comes down to the application, elemental exposure, desired look and available application equipment. There is no "right" answer and there have been volumes written on the subject, my favorite being Understanding Wood Finishing by Bob Flexner. He describes all the common finishes, how they are to be used and how to apply them. It is a must have for any woodworker.

As for a couple of questions you posed that were not addressed -

Not all finishes require sanding between coats. It depends on whether subsequent coats form a chemical or a physical bond to the previous coat. Shellac and lacquer do not require sanding because the solvent in the new coat partially dissolves the previous coat and forms a chemical bond. Varnish, polyurethane, epoxy and most paint do require sanding because subsequent coats need the "tooth" and extra surface area formed by the sanding scratches in order to physically bond to the previous coat.

Tung oil, or any oil, can give a beautiful finish if used correctly. It is a penetrating finish (up to a point) and just a couple of coats will give you that matte, smooth finish you desire while still allowing you to "feel" the wood and not the "plastic" of a surface finish. Put enough coats on, however, and it will eventually stop penetrating and start curing on the surface, and you're back to plastic. Oil finishes should be applied quite wet, allowed to penetrate for a few minutes and then wiped off - with continued wiping over the next half hour or so as the oil bleeds back out of the pores. Pure tung oil takes a very long time to cure (days), but produces a beautiful finish. Bear in mind, that most commercial products labeled "tung oil finish" by major name brands actually have very little, if any, tung oil in them. Their biggest selling feature is that they have driers in them that help the (usually linseed) oil dry. Pure tung is available, and is the best, but you must be patient as it takes a while to cure.

 

[RussF]

I forgot to add that since you have already coated your model with shellac, oil might not be the best choice for this one. Despite the fact that you sanded it back to wood, but leaving some "very small areas of Shellac left", I think that because the shellac has already penetrated the pores, the oil will have a hard time soaking in properly and if you can actually "see" areas of shellac, you'll probably be able to see them after an application of oil. Shellac is (and as Zinnser labels it), a "sealer". I think at this point, your best option would be some type of surface film finish like varnish or poly.

 

[Bob Cleek]

How about Tung Oil? Any advice on that? Looks like it is clear and acts as Sealer and finish.

Russ F has given a good response above about tung oil. In summary, I would say that tung oil is a polymerizing vegetable oil similar to safflower oil, linseed (flaxseed) oil, and many other vegetable oils. When applied in multiple coats, it presents a deep, high gloss finish. However, it does have the nasty habit of being rather slow to polymerize (i.e. "dry.") Efforts to accelerate polymerization by adding driers can result in the polymerized finish surface "wrinkling." Generally speaking, it is equal to raw linseed oil in most respects. Tung oil is a component of some quality canned varnishes.

Tung oil has gained something of a mystique in the finishing market due to advertiser's suggestions that it is something exotic and special. As there are no applicable product labeling controls on coatings, there are many products on the market sold as "tung oil," or as "containing tung oil," in fact have little, if any, tung oil in their makeup. The words "tung oil" are primarily just marketing hype, in my opinion. Fifty years ago, we played with it as an alternative to canned spar varnish on yacht brightwork with attractive, but very short-lived results as pure tung oil, which isn't cheap, has no UV inhibitors added. The conclusion was that there was little to distinguish it from raw linseed oil and nothing about it that would warrant abandoning traditional spar varnish in its favor, nor was there anything which would warrant paying any more for products that claimed to contain it. Rubbing on tung oil thinned with mineral spirits or turpentine produces a finish that is not particularly distinguishable from doing the same with raw linseed oil thinned with mineral spirits or turpentine. (Note that "boiled linseed oil" or "boiled tung oil," is not "boiled." The adjective "boiled," simply means that chemical polymerization accelerating agents are added to the oil to make it "dry" faster. A commonly used additive sold separately in paint stores is called "Japan dryer.")

As far as advice on using it goes, any finish coating should be first tested on a piece of scrap wood of the same species and color before applying it to the finished work to ensure the result is the one desired. This testing should include allowing the finish to cure fully to ensure that it will cure and not turn "gummy" or react adversely to any coating applied previously. As for shellac, as Russ F explained, it is soluble in denatured alcohol. It is not necessary to sand off unwanted shellac. It can be easily removed by wiping it off with a cloth or paper towel soaked in denatured alcohol. It is my experience that a single coat of thin clear shellac (2 or 3 pound cut, as is Zinsser's clear Bullseye straight out of the can) allowed to soak into bare wood of a quality finish wood species (e.g. pear, closed pore mahogany, oak, walnut, etc.) will provide a matte finish well-suited for modeling applications.

Depicting "bright" finishes (i.e. bare or clear-finished woods in marine applications) on models requires a very delicate treatment. Coatings on miniatures must always be as thin as possible, as the thickness of each coat incrementally "softens" detail and the actual coat thickness of most coatings greatly exceeds their "scale thickness." Conversely, fine clear "furniture" finishes rely on the thickness of the coating to create the "depth" of finish that most clear finishes are designed to produce. Additionally, the principles of "scale viewing distance" prohibit any gloss, or even "satin" or "eggshell" finish on models on scales commonly used in ship modeling. The bright finishing of entire ship model hulls, as seen on some contemporary "Navy Board" models and apparently encouraged by many model kit manufacturers, is a stylistic presentation that is currently in vogue for reasons not entirely understood by the fine arts modeling fraternity. Be that as it may, such present-day "Navy Board" replica models very frequently suffer from the excessive application of sealers, stains, and finish coatings.